The objectives of the Clinical Trials Unit (CTU) are to enroll and follow patients in ACTG protocols and contribute to ACTG protocol development. A special focus and ability of this ACTU will the enrollment of populations, specifically minorities and women, currently underrepresented in clinical trials. In addition, by virtue of extensive experience with these populations, this ACTU will be able to contribute to protocol development appropriate for minorities and women. The CTU will operate as an integrated component of the HIV Clinic, the sole provider of HIV-related ambulatory care in the institution. Study activities will occur side-by-side in the same setting as routine primary care. Patients for ambulatory studies will be screened and recruited in the context of patient care visits. Inpatient studies will be performed in a discrete dedicated AIDS Inpatient Unit. The Inpatient Unit and the HIV Clinic are currently operationally linked as the inpatient and ambulatory components of a designated AIDS Treatment Center.